Sir Martin Sorrell, CEO of the world’s largest advertising company, said Donald Trump’s move to sign an executive order temporarily barring people from seven majority-Muslim countries from travelling to the US is something the advertising mogul takes an “instinctive dislike” to.

Sorrell joins a list of high-profile business leaders — from the chief executive of Goldman Sachs to a swathe of tech CEOs — in reacting to the order, which has temporarily halted visa holders from Iraq, Iraq , Libya, Somalia, Sudan, Syria, and Yemen from travelling to the US. Refugee arrivals into the US have been barred for 120 days.

In a statement emailed to Business Insider, Sorrell said there had been no “immediate impact” to WPP and its employees in the first few days of the order, which was signed on Friday, being implemented.

However, he added: “But we are concerned about the impact it may have on our people and their families both inside and outside the USA and on innocent people generally.”

WPP employs more than 200,000 people across 113 countries.

Sorrell continued: “As the grandson of Eastern European grandparents, who were admitted to the UK in the very late 19th and early 20th centuries, I have an instinctive dislike of such measures.”

On Monday, Trump defended signing the executive order, saying on Twitter that the ban was implemented to protect the US from “bad ‘dudes’.” The day before, he released a statement saying the ban was nothing to do with region and that the US would issue visas again “once we are sure we have reviewed and implemented the most secure policies over the next 90 days”.